From a point of view of protection of a driver and/or a passenger in a car, an air bag apparatus which is a passenger protection apparatus has conventionally widely been used. The air bag apparatus is equipped for the purpose of protecting a driver and/or a passenger against shock caused at the time of collision of a vehicle, and it receives a body of a driver or a passenger with a developed air bag by instantaneously expanding and developing the air bag at the time of collision of a vehicle. A gas generator is equipment which is incorporated in an air bag apparatus and expands and develops an air bag by instantaneously generating a gas at the time of collision of a vehicle.
Depending on a position of installation in a vehicle and the like or on specifications such as output, gas generators of various constructions are available. A gas generator called a cylinder type gas generator represents one example. The cylinder type gas generator has an outer geometry in an elongated columnar shape and it is suitably incorporated in a side air bag apparatus, an air bag apparatus on a passenger's seat side, a curtain air bag apparatus, a knee air bag apparatus, or a seat cushion air bag apparatus.
Normally, in a cylinder type gas generator, an igniter is installed at one end portion in an axial direction of a housing, a combustion chamber accommodating a gas generating agent is provided in a central portion in the axial direction of the housing, a filter chamber accommodating a filter is provided at the other end portion in the axial direction of the housing, and a gas discharge opening is provided in a circumferential wall portion of the housing in a portion defining the filter chamber. In the cylinder type gas generator thus constructed, in general, a gas generated in the combustion chamber flows into the filter chamber and passes through the filter, and the gas which has passed through the filter is discharged to the outside through the gas discharge opening. In addition to the cylinder type gas generator, what is called a T-shaped gas generator is available as a gas generator having an elongated columnar outer geometry.
For example, Japanese Patent Laying-Open No. 2005-313812 (PTD 1), Japanese Patent Laying-Open No. 11-78766 (PTD 2), and WO2010/079710 (PTD 3) disclose specific structures of the cylinder type gas generator constructed as above. These publications each disclose a cylinder type gas generator in which a space in a housing is divided into a combustion chamber accommodating a gas generating agent and a filter chamber accommodating a filter by arranging a partition member in an elongated cylindrical housing having opposing ends closed.